When you cherry pick them to support your viewpoint it is not.
There was a motion made to insert the words "Our Lord, Jesus Christ" after the word "Creator" when the language of the Declaration was being debated. The founding fathers VOTED IT DOWN. They did so because they were creating a government suitable for all men. There is no reference to "God" or "Jesus" anywhere in the Constitution. There is a specific prohibition against religious tests of any sort.
Now you are cherry picking. For example:
Oliver Ellsworth, a Connecticut delegate to the Constitutional Convention of 1787, in explaining to the people the clause that prohibits a religious test for public office, stated, "A test in favor of any one denomination of Christians would be to the last degree absurd in the United States. If it were in favor of Congregationalists, Presbyterians, Episcopalians, Baptists, or Quakers, it would incapacitate more than three-fourths of the American citizens for any public office and thus degrade them from the rank of freemen."
Supreme Court Justice Joseph Story, in his 1833 Commentaries on the Constitution, stated essentially the same thing with: "The real object of the [first] amendment was, not to countenance, much less to advance Mahometanism, or Judaism, or infidelity, by prostrating Christianity; but to exclude all rivalry among Christian sects, and to prevent any national ecclesiastical establishment, which should give to an hierarchy the exclusive patronage of the national government..."
No offense, but I tend to believe the understanding of those two over any new-fangled interpretation.
Story also wrote, "The promulgation of the great doctrines of religion, the being, and attributes, and providence of one Almighty God; the responsibility to him for all our actions, founded upon moral freedom and accountability; a future state of rewards and punishments; the cultivation of all the personal, social, and benevolent virtues;- these never can be a matter of indifference in any well ordered community..."
And, "Now, there will probably be found few persons in this, or any other Christian country, who would deliberately contend, that it was unreasonable, or unjust to foster and encourage the Christian religion generally, as a matter of sound policy, as well as of revealed truth. In fact, every American colony, from its foundation down to the revolution, . . . did openly, by the whole course of its laws and institutions, support and sustain, in some form, the Christian religion; and almost invariably gave a peculiar sanction to some of its fundamental doctrines. And this has continued to be the case in some of the states down to the present period, without the slightest suspicion that it was against the principles of public law, or republican liberty."
And, "Probably at the time of the adoption of the constitution, and of the amendment to it, now under consideration, the general, if not the universal, sentiment in America was, that Christianity ought to receive encouragement from the state, so far as was not incompatible with the private rights of conscience, and the freedom of religious worship. An attempt to level all religions, and to make it a matter of state policy to hold all in utter indifference, would have created universal disapprobation, if not universal indignation..."